Internal combustion engine



E. HQ PITNEY INTERNAL COMBUSTION ENGINE Oct. 1-4, 1941.

Filed Oct. 2, 41.939

M' my @um Witt A Patented Oct. I4, 1941' UNITED. .STATES y' PATENT" oFF-ICE Application October 2, No. 297,418

3 Claims.

'I'his invention relates to internal combustion engines, and more particularly to the driving connections between the pistons and crank sha-ft.

It is an object of my present invention to provide simple and thoroughly practical mechanism for connecting the crank shaft of an internal combustion engine with the pistons in such manner as to materially increase the eiiiciency or voutput of the engine.

More specifically, it is an object to provide mechanism connecting the crank shaft with the connecting rods ofthe several pistons and controlling the effective locations of such connections throughoutthe various piston strokes, to the end that the crank arms at the topmost and lowermost positions of the .piston have passed dead center positions, and further to the. end that a, lag is produced in the movement of the pistons as the crank arms reach and pass dead center positions.

The foregoing operations are effected by a novel, shiftable,l eccentric connection between the crank pin and the connecting rodin cooperation with a means actuated by the crank movement and swinging of the connecting rod that (6) 'Cooler running is assured because even pressed in the compression stroke and the heat of combustion is spread more evenly over the entire stroke.

(7) Upon ring. pistons and rings move faster initially than with conventional structure, and consequently do not subject the oil film between the cylinder and the rings to the combination of slow movement and Ihigh pressures and temperature'.

(8) The effective length lof increased during the greater part of the power stroke, although no change in the actual stroke itself.

'I'hese and other objects and advantages of my invention will be more apparent from the following description made in connection with the accompanying drawing, wherein like reference controls the position of the eccentric throughout the up and down strokes of the piston.

As a result of the stated operation and functions ofmy mechanism, several deinite advan- (1) The eiective angle of thrust. upon the crank when the .piston is at its topmost position 'and pressures are at maximum is improved over that of engines now in wide use, and greater leverage is obtained in the downA stroke, although the length of the stroke is unchanged.

(2) The speed of the pistons down stroke is more closely matched to the rapidly diminishing characters refer to the same parts throughout the several views, and in which:

- through one of the cylinders and having incorporated therein an embodiment of my invention; Fig. 2 is a fragmentary cross section on a somewhat larger scale taken on the line 2-2 vof Fig. 1; and Figs. 3 and 4 are diagrammatic views illustrating my improved mechanism in the position of the piston in the middle of its compression stroke and in the middle of its firing stroke respectively. In the drawing, my improved mechanism` is shown as applied to a conventional type of fourcycle internal combustion engine having the usual cylinder C provided with a surrounding .water jacket W, and having working within said cylinder the reciprocating piston Pconnected by wrist pin WP with the connecting rod CR. Crank pressure in the cylinder'above, which means.

better absorption of power and, therefore, less knocking or pinging l (3) The eifect is to distribute the dow of power somewhat similar to an increase in the number of cylinders applied to an internal combustion engine. i

(4) Better control of the volume of air and/or gas mixture -is obtained because of the pistons lag at the bottom of the intake stroke. This-is case CC having the usual top T on which the cylinders are rigidly mounted is also shown. A conventional type of crank shaft CS having the usual crank pin CP is mounted for revolution of. a special advantage where aengine is working in high altitude.

(5) Burned gases are better scavenged from the cylinder because of lthe pistons lag at the top of the exhaust stroke.

below the cylinders in the crank case.

My invention, as in the embodiment illustrated, comprises mechanism forming an actuating driving connection between the lower end of the connectingvrod and the crank shaft.

In the embodiment illustrated I provide an eccentric connection between the connecting rod CR and crank pin CP which includes an eccentric in the form of a disc 6 having an eccentrically disposed bearing '6a therein. in .whichthe crank pin is journaled. vThe eccentric disc 6 has its periphery journaled in a relatively large split the crank arm is connected with the connecting rod- It The bearing is preferably channeled, as

ing I0, as shown on-the' crank case, is pivotally connected at its inner end with a shift arm 6b integrally formed or rigidly connected with disc 6.` Disc 6 is cut along Vthe line of ,achord .6x

to permit .clearance of link 8 in the lower positions of the crank shaft.

It will benoted that eccentric 6, crank and actuating link 8 are so' proportioned 'and' related that at the uppermost position of.. the

piston when firing occurs, the crank arm has passed dead center position.v In the downward ring stroke of the engine, 4eccentric 6 is moved counterclockwise due tothe Vaction Vof the crank shaft in clockwise vmovement and the actuating link 8 .(see Fig. 4) As the piston approaches the lower end of its stroke (see dotted line position in Fig. 1)', link 8 causes -theeccentric 6 t'obe moved fora small portion of a rotation in clockwise direction, thereby producing alag-in the movement of the piston. Thus it is'seen that at the start of the firing stroke, the piston moves rapidly because of the greater leverage onv the crank arm and the angularit'y between it and the connecting rod, and the down stroke =is moreperfectly matched in its application of force tothe crank shaft with the diminishing'expansion force `pin CP, v

distribution of the now of power due to Matching i speed of the pistons down stroke more evenly more on the intake stroke because of the lag which has been referred to, and will result in a cooleroperating unit meaning much greater efficiency.

It will,` of course, be understood that various changes may be made in the form, details, arrangement and'proportions of the parts without departing from the scope of my invention.

. What is claimed is: l1.".ln an internal combustion engine, the comvbination'with'a cylinder, a crank disposed below saidcylinder; a piston reciprocably mounted in said cylinder, a wrist pin and` a connecting rod, of mechanism for'chan'ging therelative position of theconnecting rod with reference to the center of the crank pin durihgthe revolutionof the crankshaft comprising, an'oscillatory member having a purely pivotal connection with the lower end of'said connecting rod and having an eccentrically disposed" bearing 'in which the 'pin of said crankis journaled, and an'actuating torque connection 'having one of its ends connected with said oscillatory member at a point eccentric to said' pivotal connectingrod connectionand ofthe explosionf'and consequently'with better drivingeiciency.

Y It will further be seen that during the time y'the piston-reaches andholds its downward limit of travel, the crank arm passes its dead center'position for the vbeginningof' the upward stroke. Greater leverage is obtained in the down stroke,

` where desired, than in the up stroke. In the up or exhaust stroke (see Fig. 3) as the piston approaches its upward position, lag again occurs giving burned gases a greater chance to be completely exhausted. In the next down stroke of the piston, the intake stroke, the lag at the lower end of the pistons travel affords a better control of volume of air and/or gas admitted, which vis of. special advantage where the engine islworking at high altitude. On the next, or compression up stroke, thecompression 'is held at a maximum in the position shown in Fig. 1, while the crank armv passes dead center position and until ring occurs. Also, fthe disc could be so positioned as not to'attain maximum compression until after de ad center. I 'f` f In the embodiment illustrated (see Fig. 1) the piston in .its up strokes, kboth compression and exhaust, .remainsin its topmost position, indicated in full lines, d uring the movement of the crank arm and kcrank pin throughthearc A due to the fact'. that the axis of the eccentric disc 6 is 'simultaneously swung in the opposite direction through the ,arcBL From Lthe foregoing it will be seen that with mystructure the applicationof power upon the crank shaft at va more effective angle during firing stroke, the effectiveness of the lag in completing `the exhaust stroke,v `the advantages in better control'zof the combustive mixture, and the 75 ward--strokearld a lag Ofj said pistonin 'its exfy also eccentric to said crank pinA bearing and adjacent the longitudinal center line of said connecting rod when said piston is in uppermost position, said torque connection extending transversely of the axis of said crank and having its outer endl pivoted to an anchorng member disposed at somev distance to one side of the longitudinal center line of said piston, the length of said torque connection and its relation to said oscillatory memberl and the bearing for said crank pin being such that in the reciproation of said piston a lag occurs in the upper movement thereof and said crank pinA moves past dead center relation with the axis of said crank and said wrist pin before said piston starts its downward movement, and that the downwardvmovement of said piston is relatively rapid during.

said cylinder,.a piston reciprocably mounted in,

said cylinder, a wrist pinA and a connecting' rod, of a `crank connection shifting` member having a purely pivotal'connection with said connecting rod and having a bearing disposed eccentrically of said pivotal connection in which the pin of 'said crank journaled, andan actuating torque connectionv pivotally connected with said shifting member at one of'its ends' and pivoted to anchoringmeans at its opposite end for shifting the position of the' pivotal connection of saidcrank with saidconnecting rod trans-g versely of4 "said l'rod during revolution-of said crank to provide for relatively yrapid'movel'nent l,of saidpiston during t vrst partofi-ts downtreme upper movement, and movement of said crank pin past dead center relation between the crank axis and wrist pin before said piston is moved past uppermost position.

3. In an internal combustion engine, the combination with a cylinder, a crank disposed below said cylinder, a piston reciprocably mounted in said cylinder, awrist pin and a connecting rod, of a crank connection shifting disc having a purely pivotal connection with said connecting rod and having a bearing disposed eccentrically of said pivotal connection in which the pin of said crank is joumaled, and an actuating torque link having one of its ends connected with said disc for applying torque thereon, said torque connection being at a point adjacent the line of said connecting rod when said piston is in uppermost position, said link extending transversely oi' the axis of said crank and being disposed substantially horizontal when said piston has completed half its stroke, the other end of said torque link.A being pivoted to an anchoring member disposed atsome distance to one side of the longitudinal center line of said piston, the relationship of said crank pin bearing to the .torque connection of said link in cooperation with the recited structure causing relatively rapid movement of said piston during the rst part of its downward stroke and a lag of said piston in its extreme upper movement andmovement of said crank pin past dead center relation between the crank axis and wrist pin before said piston is moved past uppermost position.

' EARL H. PITNEY. 

